<!DOCTYPE html>
<html lang="en" xmlns:v-on="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<div id="app10">
    <p>{{ foo }}</p>
    <!-- 这里的 `foo` 不会更新！ -->
    <button v-on:click="foo = 'baz'">Change it</button>
</div>
<script type="text/javascript">
    var obj = {
        foo: 'bar'
    }

    Object.freeze(obj)

    new Vue({
        el: '#app10',
        data: obj
    })
</script>
</body>
</html>